The Research Of Free-contact Ultrasonic Hydraulic Pressure Measurement Method

Pressure is one of the most important parameter of hydraulic system. It can reflect directly that whether hydraulic system is in good performance. Ultrasonic may carry out the pressure signal of hydraulic system when it passes the liquid. So we can get the pressure size of hydraulic system in virtue of ultrasonic velocity through conversion. This is a free-contact pressure measurement method, and it has huge advantage in convenient installation, turndown hydraulic system state and no excess pressure drop in compare with traditional contact pressure measurement method. It is a very preferable hydraulic pressure measurement instrument adapting to the occasion of worse condition and system malfunction and so on. However, large data indicates that the research of free-contact pressure measurement method belongs to exploring phase, and the method is good for the research. A single-chip microcomputer measurement system has been designed on the base of mature theory in testing flow and its instrument. A reasonable pulse-echo method is chosen to test ultrasonic velocity. The artificial neural networks are used to build the system model of ultrasonic velocity and hydraulic pressure. Then an experiment ultrasonic hydraulic pressure measurement instrument is developed which is vitally settled in the circuit of driving sensor, automatic controlling gain and controlling receiving sensor. Of course, an anti-jamming methods are used in software and hardware, including photoelectric coupling circuit, filter circuit and insulating drive circuit and so on. As a word, the method put forward is feasible from the primary research of the measurement system.